坝上地区农田和恢复生境地表甲虫多样性

研究采用陷阱法对河北坝上崇礼县农田、禁牧草地及再造林地3种常见生境中地表甲虫进行了取样调查,分别从鞘翅目分科、步甲分种两个分类水平比较分析了不同生境中的生物多样性状况以评估生境恢复状况及其对生物多样性的影响,并探索在以生物多样性为指标评估生境恢复状况过程中,研究结论是否受分类水平的影响。结果显示,草地和林地具有较为相似鞘翅目和步甲的结构组成,但均显著不同于农田。农田较再造林地和禁牧草地具有更多的鞘翅目科数及步甲物种数,且均显著高于林地;农田中步甲群落的Fisher's α多样性指数也显著地高于林地,但鞘翅目分科水平上的Fisher's α多样性指数在各生境中没有差异。结果说明:(1)再造林和草地禁牧的生境修复活动在当前状态下对生物多样性恢复的作用尚不明显,仅是表现出促进了景观尺度上较高的Beta和Gamma多样性,而农田则在维持当地较高的生物多样性中扮演重要角色;(2)在鞘翅目分科和步甲科分种研究数据所反映的不同生境条件下的多样性和组成状况基本相同,因此在需要快速评估生境恢复状况且物种水平鉴定存在困难的时候,可以采用鞘翅目分科的数据替代指示生境恢复的状况并反映生境恢复对生物多样性影响的趋势,从而减少分类的难度并提高工作效率。但是物种水平的多样性状况更能显著反映生境间的差异。     

黄淮平原农业景观鸟类多样性及生境差异

农业景观中的鸟类多样性对生态系统功能和服务的形成与维持具有重要作用。黄淮平原区是我国最重要的农业景观区之一,为探讨区域内农业景观中鸟类多样性特征和不同生境间的差异,在研究区农业景观不同生境中布设样点,调查繁殖期鸟类多样性特征。结果显示:(1)共记录到32科、49属、66种的10044只个体,但优势科属明显;(2)物种丰富度、多样性和均匀度均表现出在沟渠、湖泊生境中较高,农田和村庄生境中相对较低,但物种多度呈现出村庄生境中最高,其次是沟渠和农田生境,湖泊生境中最低;(3)在区系分布上,各生境中均以广布种为主,生态类群上,鸣禽在各生境中均占绝对优势,涉禽和游禽主要分布在沟渠和湖泊生境中,从居留型来看,留鸟是各生境中的主导类群,候鸟、旅鸟和迷鸟比例很低;(4)鸟类群落异质性分析显示,各生境间的相似性总体上较高,表明区域内农业景观中鸟类组成具有较高的重叠性。研究显示农业景观中湖泊和沟渠的存在能有效的提高区域鸟类的丰富度和多样性,而沟渠的存在能有效的提高鸟类个体多度,农田和村庄有助于特定类群多度的增加,因此在未来的区域持续农业景观的构建中一方面要重视自然、半自然非农生境的作用,另一方面也不能忽视不同生物类群对景观异质性响应和对生境特征需求的差异。     

半自然农田边界与相邻农田步甲和蜘蛛的时空分布

分别于小麦、玉米收获前后,采用陷阱法调查了华北地区典型农业景观中具有不同植被结构的农田边界及其相邻农田中两类重要天敌类群步甲和蜘蛛的多样性.通过比较农田生境及相邻农田边界间两类天敌群落的时空分布格局及其与相邻半自然生境植被群落的相关关系,探讨半自然农田边界对两类天敌类群的保护作用.结果表明: 整个取样季节农田边界处蜘蛛的多度显著高于农田内部;而步甲多样性在农田与边界间无显著性差异,仅呈现不同的群落结构;作物收获后蜘蛛分科数在边界处的增加以及在农田的减少,显示了蜘蛛在农田和边界之间的迁移活动.边界植被结构对蜘蛛和步甲多样性有不同影响:边界较高的草本层盖度和较低的乔木层盖度有利于增加农田中某些步甲优势种的多样性;而较高的草本层盖度有利于增加皿蛛科蜘蛛的多样性.因此,半自然生境的存在可以通过天敌在农田和边界之间的迁移运动促进农田天敌多样性的维持;但不同类型半自然生境植被群落结构可能影响其对不同天敌群落多样性的维持和保护作用.为促进农业景观对天敌的保护作用,提高其害虫控制功能,需要深入了解不同天敌的生境需求及食物需求,精心设计有利于天敌多样性维持的半自然生境.     

北京密云农业景观步甲群落空间分布格局

采用陷阱法对北京密云县西田各庄南部农业景观中玉米地、花生地、果园及半自然林地4种典型生境中的步甲群落进行调查分析.结果表明:果园步甲群落α多样性最高,花生地最低,林地与玉米地居中,且二者无显著差异;林地、花生地及果园的步甲群落结构明显不同,但均与玉米地的步甲群落结构有不同程度的相似性.果园维持着较多的捕食性步甲和兼食性步甲个体数;且不同生境间捕食性步甲的物种周转率与兼食性步甲的差异更明显.低集约化的果园生境可能较半自然生境林地维持更高的步甲群落α多样性,但多样化的景观组成有利于维持步甲群落及捕食性步甲较高的β多样性.重视景观多样性和低集约化农田生境的保护对保护农业景观步甲群落多样性和实现其害虫控制功能具有重要的意义.     

坝上地区农田及两种恢复生境中蜘蛛多样性与群落特征

蜘蛛是农田生态系统中重要的自然天敌,其生物多样性及群落特征直接决定了农田的害虫控制等生态系统服务功能质量。农田及其周边的恢复生境是蜘蛛重要的栖息地。本研究采用陷阱法,对河北省张家口市崇礼区871、1360、1635 m 3个海拔农田、自然恢复草地及人工修复林地的蜘蛛群落的物种组成、物种多样性和功能特征进行研究,分析不同恢复生境中蜘蛛群落特征。结果表明: 不同生境蜘蛛的物种多样性指数差异明显,人工修复林地蜘蛛的多度为124.3只,显著高于自然恢复草地(70.1)及农田(38.6)的蜘蛛多度;人工修复林地(16.3)与自然恢复草地(21.4)的物种丰富度没有显著差别,但均显著高于农田(8.9);人工修复林地(2.04)及自然恢复草地(2.05)的Shannon多样性指数差异不显著,且均显著高于农田(1.55)。3种生境的蜘蛛群落组成均具有显著差异;蜘蛛体长与蜘蛛捕猎类型呈正相关,大型蜘蛛倾向于通过捕猎获取食物;自然恢复草地与农田蜘蛛以游猎型为主,而人工修复林地倾向于拥有更多的结网型蜘蛛,高海拔地区的蜘蛛体积通常较小。自然恢复草地与人工修复林地均可以提升蜘蛛群落多样性,在区域生物多样性保护中起重要作用;不同生境蜘蛛群落组成出现了显著分化,即蜘蛛群落总体的功能特征发生改变和保留了部分生境特有种。2种恢复生境蜘蛛多样性指标优于农田生境,且2种恢复生境物种组成存在差异,均具有保护特有种的功能,研究结果对农田及区域尺度蜘蛛生物多样性保护与恢复具有指导意义。     

鹞落坪保护区四种不同生境的夏季鸟类多样性差异

研究不同生境中鸟类群落的差异可以为其管理与保护提供科学依据。于2017年7—8月在鹞落坪国家级自然保护区的不同海拔区域内开展夏季森林鸟类群落调查, 并分析鸟类群落在森林、公路、村村通和村庄等生境之间的差异。结果共调查到78种4225只鸟, 隶属于9目30科。由于较高的郁闭度和较单一的植被类型, 森林生境中的鸟类物种数、个体数和多样性指数均较低, 与穿越森林的公路无显著差异。尽管村村通和公路生境的鸟类个体数与多样性指数没有显著差异, 但村村通生境中鸟类物种数显著高于公路生境, 仅次于村庄, 这可能与其较高的开阔度和较低的干扰有关。村庄鸟类物种数、个体数和香农威纳多样性指数均显著高于其他生境, 这可能与村庄比较开阔的生境和丰富的食物资源有关。研究结果表明, 在森林景观中, 村落等干扰较大的生境中夏季鸟类群落物种多样性较高。     

松嫩平原不同生境蝴蝶群落多样性及其保护建议

随着气候变化加剧和人类活动影响，生物多样性变化及其保护逐渐受到广泛关注。蝴蝶作为开花植物的传粉媒介和生态环境监测及评价的关键指示者，其多样性变化能够在一定程度上反映生境状况，因此，有必要清晰认识不同生境中的蝴蝶多样性变化。为明确松嫩平原蝴蝶资源和不同生境的群落多样性差异，采用样线法于2016年5月-2018年8月对松嫩平原的割草草地、湿地、农田、放牧利用草地及恢复草地共五种生境类型进行调查研究。结果发现，调查共记录蝴蝶5108头，隶属于6科21属26种，其中牧女珍眼蝶（Coenonympha amaryllis）和红珠灰蝶（Plebejus argyrognomon）为优势种类，分别占蝴蝶个体总数的25.61%和31.66%，且在五种生境类型中均有分布。不同生境类型中，蝴蝶群落的物种丰富度指数和均匀度指数无明显差异，而恢复草地生境的蝴蝶群落Shannon-Wiener多样性指数较高，优势度指数较低。农田生境中的蝴蝶个体数量较少，且群落组成与其他四种生境之间均具有显著差异。五种生境类型中的蝴蝶数量和多样性均呈现一定的月动态和年动态变化趋势。除湿地和农田外，其余三种生境中蝴蝶物种和个体数量从5月到8月均持续升高。四种生境的蝴蝶物种数量、个体数量（除农田外）在2018年均出现明显下降趋势。物种丰富度指数等指标的月动态和年动态在不同生境类型间存在较大差异。这些结果表明，生境类型和人类活动与蝴蝶多样性变化关系密切，表现为单一生境中蝴蝶多样性较低，复杂生境有利于保护蝴蝶多样性。本研究有助于厘清松嫩平原蝴蝶资源的基础数据，并为该地区蝴蝶多样性保护和利用及评估该区域生态环境提供一定理论支撑。     

黄河下游平原不同非农生境中植物多样性

自然、半自然等非农生境是区域农业景观的重要组成部分,对区域生物多样性保护具有重要意义。黄河下游平原区是典型的农业景观,农田是最主要的景观类型,林地、树篱等景观要素散布其中,为研究区内非农生境中生物多样性及其生态效应,采用典型样地法对区内典型农业景观中林地、树篱、田间道路和沟渠等主要非农生境中的植物群落进行调查研究。结果显示:区内植物组成以菊科、禾本科等为主;区内植物科的地理成分以世界分布和泛热带分布为主,各生境间有一定的差异,属的地理成分复杂,具有中国15个种子植物属分布型中的13个,以温带分布、世界分布和泛热带分布为主,总体上区内的植物组成以广布种为主,优势科属明显,特有种缺乏;各非农生境中的植物多样性存在一定的差异,林地和树篱生境具有较高的物种丰富度和多样性,显著高于田间道路,沟渠、林地和树篱生境中的物种均匀度和群落盖度均显著高于田间道路;β多样性分析表明田间道路生境中的群落组成分化程度在各样点间最大(β多样性指数最高);树篱、林地和田间道路等生境间群落相似性均较高,但其群落结构和优势种组成方面却存在显著的差异,沟渠作为一种特殊生境与其它生境间的群落相似性相对较低。研究表明,在黄河下游平原典型农业景观中,作为非农生境存在的林地和树篱在物种多样性维持中具有重要地位,沟渠为水生和湿生植物提供了庇护所,意义重大;各生境间高的群落相似性仅是物种组成名录相似性的反映,其空间格局和优势种群间差异明显,各生境植物群落的生态功能差异巨大。未来区内生物多样性的保护应重在生态系统过程、功能的加强以及生态系统服务的维持和提高,且需进一步在景观水平上探讨各非农景观要素的空间构型对其生态效益的影响机制及其调控和管理策略。     

农业景观步甲多样性时间格局及其与景观结构的关系

于2009年5-9月在北京密云县采用陷阱法对玉米地、花生地、果园和林地4种生境中步甲群落进行取样,并采用逐步线性回归分析了景观中优势生境类型——玉米地中步甲群落及其捕食性步甲功能群多样性的季节分布,及其与周围100、250和500 m半径范围内景观格局指数的关系.结果表明:不同生境下,8月步甲群落、捕食性步甲类群的个体数和物种数均达到最大;5月玉米地中步甲群落的物种数与取样点100 m半径范围内的景观连接度呈正相关,8月步甲群落个体数和500 m半径范围内的景观连接度呈负相关;5月玉米地中捕食性步甲群落不论是个体数还是物种数均与取样点100 m半径范围内景观连接度呈正相关,而8月捕食性步甲的物种数则与100 m尺度范围内的半自然生境的类型数呈负相关.可见,景观连接度、半自然生境的类型数对步甲及其中捕食性步甲群落动态的关键季节的多样性状况有显著影响,合理规划农田半自然用地类型组成、增加景观连接度可促进步甲群落多样性保护及其害虫生物控制功能的发挥.     

不同农业景观背景下传粉昆虫群落的分布差异

农业景观中的自然、半自然生境等非农生境可为传粉昆虫提供丰富的食物来源、栖息地、繁殖地、避难所等,对维持生物多样性的稳定起着不可替代的作用。以巩义典型的山地-丘陵-河川混杂的复杂景观和民权的平原农业简单景观为研究区,分析不同景观背景下传粉昆虫群落的物种组成及其在不同生境中的分布特征。结果表明:(1)巩义研究区内累计捕获传粉昆虫18582头,民权研究区内累计捕获传粉昆虫18518头,优势传粉昆虫功能群为双翅目、膜翅目、鞘翅目和鳞翅目等;(2)景观复杂度更高的巩义研究区的传粉昆虫多样性、丰富度以及均匀度均显著高于民权研究区;存在大面积农田斑块的平原景观中则有更多的优势传粉昆虫个体;(3)农田斑块中具有更高的物种丰富度,但林地物种的多样性和均匀度则相对稍高些。农田斑块在作物花期能有效的提高传粉者种群密度,但林地等自然、半自然生境对于维持传粉者多样性和食物缺乏期种群的稳定具有重要作用。因此在未来为确保农业景观中传粉者的多样性与传粉服务的稳定,一方面要关注自然、半自然生境的作用,同时也要考虑不同景观背景下异质性特征对不同生物类群的影响差异。     

Genetic diversity of the subterranean Gansu zokor in a semi-natural landscape

We studied the relationship between genetic diversity of the subterranean Gansu zokor Myospalax cansus and habitat variability in the Loess Plateau, Qinghai Province, China. We used a combination of geographic information systems and molecular techniques to assess the impact of habitat composition and human activities on the genetic diversity of zokor populations in this semi-natural landscape. Although they occurred relatively infrequently in the landscape, woodland and high-coverage grassland habitats were the main positive contributors to the genetic diversity of zokor populations. Rural residential land, plain agricultural land and low-coverage grassland had a negative effect on genetic diversity. Hilly agricultural land and middle-coverage grassland had little impact on zokor genetic diversity. There were also interactions between some habitat types, that is, habitat types with relatively better quality together promoted conservation of genetic diversity, while the interaction between (among) bad habitat types made situations worse. Finally, habitat diversity, measured as patch richness and Shannon's diversity index, was positively correlated with the genetic diversity. These results demonstrated that: (1) different habitat types had different effects on the genetic diversity of zokor populations and (2) habitat quality and habitat heterogeneity were important in maintaining genetic diversity. Habitat composition was closely related to land use thus emphasizing the importance of human activities on the genetic diversity of subterranean rodent populations in this semi-natural landscape. Although the Gansu zokor was considered to be a pest species in the Loess Plateau, our study provides insights for the management and conservation of other subterranean rodent species.     

Landscape- and time-dependent benefits of wildflower areas to ground-dwelling arthropods

Wildflower areas are a popular agri-environment scheme to counteract agro-biodiversity loss. Yet, their benefits are controversially discussed. Since inconsistent benefits may be owed to landscape context and temporal dynamics, we applied a multi-year study to unravel effects of permanent and transient habitats on ground-dwelling arthropods in wildflower areas and cereal fields.Across three consecutive years, we studied activity density, species richness and community composition of rove beetles, carabid beetles and spiders in ten pairs of wildflower areas and cereal fields along independent gradients of proportions of permanent semi-natural habitats or transient wildflower areas.Arthropod responses to the proportions of permanent semi-natural habitats often followed a hump-shaped pattern, whereas transient wildflower areas seemed to drive linear responses. An interactive effect on rove beetle richness in wildflower areas implies that benefits were highest either at intermediate proportions of permanent semi-natural habitats or at lower proportions, but with additional availability of transient wildflower areas or in landscapes with low proportions of permanent semi-natural habitats, but high proportions of wildflower areas. However, ground-dwelling arthropod activity density or species richness did not systematically increase over the three study years.Our results suggest that both permanent and transient habitats differ in how they affect biodiversity, possibly due to different temporal continuity and resource diversity. Benefits of permanent semi-natural habitats seemed highest at an equilibrium between an increasing resource-related species pool and an increasing diversity dilution, whereas benefits of transient wildflower areas seemed to increase with resource complementarity and connectivity at the landscape scale. Nevertheless, both habitats seem to complement each other and considered in concert, seem to be most effective in promoting benefits of wildflower areas to ground-dwelling arthropods at intermediate landscape complexity. The substantial variation in diversity patterns among years with weather extremes, suggests that optimizing benefits of wildflower areas requires further multi-year studies.     

Determinants of diversity in afrotropical herbivorous insects (Lepidoptera: Geometridae): plant diversity,vegetation structure or abiotic factors?

Aim This study was conducted to investigate the potential of predicting alpha diversity and turnover rates of a highly diverse herbivorous insect family (Geometridae) based on vascular plant species richness and vegetation structure. Location The study was carried out on the south‐western slopes of Mount Kilimanjaro within a wide range of habitats between 1200 and 3150 m elevation. Methods The floristic and structural composition of the vegetation was recorded at 48 plots of 400 m². Geometrid moths were sampled manually at light sources located at the plot centres. Principal components analysis, redundancy analysis and multiple linear regression were used to explore how alpha diversity and species turnover of geometrid moths are related to vegetation structure and plant species richness. Results Alpha diversity of geometrid moths was significantly correlated with species diversity patterns in the most common vascular plant families (R² = 0.49) and with plant structural parameters (R² = 0.22), but not with overall floristic diversity. Species turnover of geometrid moths was strongly linked to diversity changes in a range of plant families (40% explained variance), less strongly to changes in vegetation physiognomy (25%), and only weakly to overall floristic diversity (5%). Changes in elevation were a better predictor of both alpha diversity and species turnover of geometrid moths than any principal component extracted from the vegetation data. Main conclusions Vegetation composition, diversity and structure all showed significant correlations with the diversity and species composition of geometrid moth assemblages. Nevertheless, in most cases relationships were indirect, via environmental parameters such as temperature and humidity, which influenced both vegetation and moth fauna. Possible direct links between geometrid diversity and potential food plants were much weaker. The lack of a significant correlation between overall plant species richness and geometrid diversity indicates that tropical geometrid moths may not be very selective in their food plant choice. Accordingly, a clear correlation between floral diversity and herbivore species richness must be regarded as overly simplistic, and the diversity of vascular plants cannot universally be used as a suitable biodiversity indicator for diverse insect taxa at higher trophic levels.     

冀西北坝上地区的夜蛾科昆虫

系统调查研究冀西北坝上农牧交错带的鳞翅目Lepidoptera,夜蛾科Noctuidae蛾类,已知11亚科71属117种,并对其多样性做了分析。各月份蛾类组成及数量差异较大,从5月到9月蛾类多样性指数、物种丰富度和个体数基本呈上升趋势,多样性指数与均匀度(r=0.9943)、丰富度(r=0.8979)相一致。而不同月份间的蛾类相似程度差异较大。     

Richness and composition of herbaceous species in restored shrubland and grassland ecosystems in the northern Loess Plateau of China

Restored grasslands and shrublands are integral parts of the semi-natural landscape and are of major importance for biodiversity in the northern Loess Plateau. Determining the underlying factors that control the richness and composition of herbaceous species in restored grasslands and shrublands is urgently needed. Thus, the specific objective of this study was to evaluate the relative importance of soil, plant, and topographic explanatory variables affecting the richness and composition of herbaceous species in restored shrubland and grassland ecosystems in a typical watershed within the northern Loess Plateau. In this study, 27 restored grassland sites and 16 restored shrubland sites were sampled during September 2009. Using variation partitioning (partial canonical correspondence analysis), we determined the individual and shared effects of these three sets of explanatory variables on herbaceous biodiversity in the two restored habitats. Most of the explained variation in plant diversity was related to the pure effect of soil, plant, and topographic variables. Restored shrublands had significantly more species than grasslands, and abandoned dam farmlands had significantly more species than other grassland sites. Moreover, botanical diversity responded differently to the explanatory variables in different plant communities. The pure effects of soil properties, soil moisture in particular, accounted for the largest fractions of explained variation in species diversity in restored grasslands. Both plant and topographic variables had balancing pure effects on species diversity in restored shrublands, in particular the shrub density and slope angle. We conclude that the maintenance of a moderate density of shrubs (less than 3600 shrubs per ha), construction of check-dams, and grazing at a low stocking rate, taking conditions of soil and topographic site into account, may help to conserve biodiversity in the northern Loess Plateau.     

Woody elements benefit bird diversity to a larger extent than semi-natural grasslands in cereal-dominated landscapes

Increasing landscape complexity can mitigate negative effects of agricultural intensification on biodiversity by offering resources complementary to those provided in arable fields. In particular, grazed semi-natural grasslands and woody elements support farmland birds, but little is known about their relative effects on bird diversity and community composition. In addition, the relative importance of local habitat versus landscape composition remains unclear. We investigated how the presence of semi-natural grasslands, the number of woody elements and the composition of the wider agricultural landscape affect bird species richness, true diversity (exponential Shannon diversity) and species composition. Bird communities were surveyed four times on 16 paired transects of 250 m each with 8 transects placed between a crop field and a semi-natural grassland and 8 transects between two crop fields with no semi-natural grasslands in the vicinity. The number of woody elements around transects was selected as an important predictor in all models, having a positive effect on species richness and true diversity, while the local presence of semi-natural grasslands was not selected in the best models. However, species richness and true diversity increased with increasing cover of ley and semi-natural grasslands, whereas species composition was modified by the coverage of winter wheat at the landscape scale. Furthermore, bird species richness, true diversity and species composition differed between sampling dates. As bird diversity benefited from woody elements, rather than from the local presence of semi-natural grasslands as such, it is important to maintain woody structures in farmland. However, the positive effect of grassland at the landscape scale highlights the importance of habitat variability at multiple scales. Because species richness and true diversity were affected by different landscape components compared to species composition, a mosaic of land-use types is needed to achieve multiple conservation goals across agricultural landscapes.